Leetcode Implement Stack using Queues

Implement the following operations of a stack using queues.

• Push (x)-push element x onto stack.
• Pop ()--Removes the element on top of the stack.
• Top ()--Get the top element.
• Empty ()--Return whether the stack is empty.

Notes:

• You must the only standard operations of a queue – which means only push to back ,, peek/pop from front size , and is empty operations AR E valid.
• Depending on your language, queue May is not supported natively. You could simulate a queue by using a list or deque (double-ended queue), as long as if you have standard operations of a Q Ueue.
• You may assume this all operations is valid (for example, no pop or top operations would be called on an empty stack).

classStack {Private: Queue<int> que[2]; intCurrent ; voidTransfer (queue<int>& que1, queue<int>& Que2,intN) { for(intI=0; i<n; i++) {Que2.push (Que1.front ());        Que1.pop (); }    }  Public: Stack (): Current (0){}    //Push element x onto stack.    voidPushintx) {que[current].push (x); }    //removes the element on top of the stack.    voidpop () {intNums =que[current].size (); if(Nums = =0) {            return; } transfer (Que[current], que[1-current], nums-1);        Que[current].pop (); Current=1-Current ; }    //Get the top element.    intTop () {if(Empty ()) {return 0; }        returnQue[current].back (); }    //Return Whether the stack is empty.    BOOLempty () {returnQue[current].empty (); }};

You can also use a queue to complete, but for the queue one and two are no different than just a pointer.

Leetcode Implement Stack using Queues